Comparative analysis of adaptive statistical iterative reconstruction-V (ASiR-V) and non-ASiR-V performance in dose...

Pediatric chest computed tomography (CT) requires optimization of image quality while minimizing the radiation dose, especially for low-contrast anatomical structures. This study aimed to develop and utilize novel, Various Age-size Pediatric Chest Phantoms (VAPC) models for 1-, 4-, and 7-year-old pediatric patients to systemically evaluate the effect of varying adaptive statistical iterative reconstruction-Veo (ASiR-V) levels under dose conditions consistent with American Association of Physicists in Medicine Report 246 recommendations for pediatric chest CT (as detailed in the Methods section). Phantom models were generated from datasets in the Digital Imaging and Communications in Medicine format, obtained from The Cancer Imaging Archive, and scanned using five protocols with Adaptive Statistical Iterative Reconstruction-Veo (ASiR-V) levels of 20%, 40%, 60%, and 80%. The absorbed doses in the lungs, soft tissue, spine, and heart were measured using Gafchromic LD-V1 films. The image quality was evaluated using the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and noise power spectrum. Increasing the ASiR-V percentage consistently improved image quality, with 80% ASiR-V producing significant SNR gains (e.g. 5.63-7.93, in 1 year-old), increased CNR, and 42%-61% noise reduction compared with filtered back projection. The 1 year-old phantom showed an 80.7% reduction in lung dose (2.99-0.58 mGy), and the 4 year-old phantom showed a 42.01% reduction in lung dose (3.07-1.78 mGy) at the same parameters (80% ASiR-V). In contrast, the 7 year-old phantom showed the largest gain in image fidelity. Overall, ASiR-V showed optimal performance in younger phantoms (1 year) while maintaining anatomical details and achieving improved dose efficiency in the 7 year-old phantom, supporting its effectiveness for low-dose pediatric chest-CT imaging.